The invention relates to a marine drive having two counter-rotating surface operating propellers.
The present invention arose during development efforts directed toward a marine drive enabling increased top end boat speed. This is achieved by raising the torpedo or gear box out of the water to reduce drag, and by using two counter-rotating surface operating propellers. Surfacing drives are known in the art, for example U.S. Pat. No. 4,871,334, column 3, lines 35+.
The present invention provides structure effective during initial boat acceleration to aid in getting the boat up on plane, i.e. from a submerged condition of the propellers to a surfacing condition of the propellers. A planing plate extends rearwardly from the drive housing and pushes down on the surface of the water during initial boat acceleration to in turn lower the bow and aid in getting the boat up on plane.
In a further aspect of the invention, the drive housing includes right and left inclined splash plates extending from the torpedo portion rearwardly and upwardly at an incline and meeting the planing plate.